Sen. Barbara Boxer and Sen. Dianne Feinstein are calling on a Democratic California state senator to resign following his arrest on public corruption and firearms charges.

Boxer and Feinstein on Thursday joined the Democratic leader of the state Senate and others in demanding Sen. Leland Yee resign or face suspension by his colleagues. So far, Yee has only announced he is dropping out of the Secretary of State race.

Yee’s lawyer says the senator plans to plead not guilty to charges of accepting more than $42,000 to influence legislation and introduce an undercover FBI agent to an arms trafficker.

Feinstein once lauded a gang leader known as “Shrimp Boy,” who was among two dozen people charged in the investigation.